CVE-2017-16740
📋 TL;DR
A stack-based buffer overflow vulnerability in Rockwell Automation Allen-Bradley MicroLogix 1400 controllers allows remote attackers to execute arbitrary code. This affects Series B and C controllers running vulnerable firmware versions, potentially compromising industrial control systems.
💻 Affected Systems
- Rockwell Automation Allen-Bradley MicroLogix 1400 Controllers
📦 What is this software?
1766 L32awa Firmware by Rockwellautomation
1766 L32awaa Firmware by Rockwellautomation
1766 L32bwa Firmware by Rockwellautomation
1766 L32bwaa Firmware by Rockwellautomation
1766 L32bxb Firmware by Rockwellautomation
1766 L32bxba Firmware by Rockwellautomation
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to take control of industrial processes, modify logic, disrupt operations, or cause physical damage.
Likely Case
Remote code execution leading to unauthorized access, data manipulation, or denial of service affecting industrial operations.
If Mitigated
Limited impact with proper network segmentation and access controls preventing exploitation attempts.
🎯 Exploit Status
Buffer overflow vulnerability that could be exploited remotely without authentication
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 21.003 or later
Vendor Advisory: https://rockwellautomation.custhelp.com/app/answers/detail/a_id/1070883
Restart Required: Yes
Instructions:
1. Download firmware update from Rockwell Automation website. 2. Backup current configuration. 3. Apply firmware update via programming software. 4. Restart controller. 5. Verify firmware version.
🔧 Temporary Workarounds
Network Segmentation
allIsolate MicroLogix controllers in separate network segments with strict firewall rules
Access Control Lists
allImplement strict network access controls to limit communication to authorized systems only
🧯 If You Can't Patch
- Implement strict network segmentation and firewall rules to isolate controllers
- Monitor network traffic for anomalous communication patterns and implement intrusion detection
🔍 How to Verify
Check if Vulnerable:
Check controller firmware version via RSLogix 500 or similar programming softwareCheck Version:
Use RSLogix 500 software to read controller properties and check firmware versionVerify Fix Applied:
Verify firmware version is 21.003 or later and test controller functionality📡 Detection & Monitoring
Log Indicators:
- Unusual network traffic patterns
- Unexpected controller resets
- Communication errors
Network Indicators:
- Anomalous traffic to controller ports
- Unexpected protocol communications
SIEM Query:
source_ip:external AND dest_ip:controller_ip AND (port:44818 OR port:2222)🔗 References
- http://www.securityfocus.com/bid/102474
- https://ics-cert.us-cert.gov/advisories/ICSA-18-009-01
- https://rockwellautomation.custhelp.com/app/answers/detail/a_id/1070883
- http://www.securityfocus.com/bid/102474
- https://ics-cert.us-cert.gov/advisories/ICSA-18-009-01
- https://rockwellautomation.custhelp.com/app/answers/detail/a_id/1070883
